Turbine engine impellers of Ti-6Al-4V are currently being used both by gas turbine engine manufacturing companies in the USA and abroad for use at temperatures of up to 300.degree. C. However, while the low cycle fatigue (LCF) life is generally good, it would be preferable to have better fatigue performance to extend the design life of such rotating components. This invention is directed toward this goal. Other benefits are also obtained, as will become apparent from that which follows.